JP2511344Y2 - Dynamic damper mounting structure for automobile exhaust system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a dynamic damper mounting structure for an automobile exhaust system, and in particular, cancels vibrations from the exhaust system side of an internal combustion engine to avoid a resonance frequency. The present invention relates to a dynamic damper mounting structure for an automobile exhaust system.

[Prior Art] In an internal combustion engine of a vehicle, an exhaust pipe in which a catalytic converter is provided in the middle of the exhaust pipe is connected to an exhaust manifold in order to guide the exhaust gas from the combustion chamber to the outside air to the exhaust system of the internal combustion engine. are doing. In the catalytic converter, a catalytic body configured to support, for example, a three-way catalyst that reacts with exhaust gas is stored in a catalyst case.

The exhaust pipe is supported by an exhaust pipe support device in order to prevent the catalyst of the catalytic converter from being damaged by twisting of the entire exhaust pipe due to vibration of the internal combustion engine side or vibration of the vehicle body side.

The dynamic damper mounting structure for the automobile exhaust system is disclosed in Japanese Utility Model Publication No. 53-82933 (Japanese Utility Model Publication 55-51622).
Japanese patent publication). The exhaust system vibration damper for an automobile disclosed in this publication is provided with a bolt that integrally joins the flanges of the exhaust pipe of the automobile to each other, and a heavy cone having a required mass is integrally formed on the bolt to exhaust the exhaust gas. The muffler system vibration at the resonance of the system pipe is reduced.

In order to suppress the vibration of the internal combustion engine of the automobile, a method of mounting a dynamic damper has been conventionally used.

However, a dynamic damper is not attached to the exhaust pipe, but a mass damper is mainly provided to remove the resonance frequency of the exhaust pipe from the normal rotation speed range.

[Problems to be Solved by the Invention] By the way, in the conventional damper mounting structure for an automobile exhaust system, the dynamic damper is not mounted on the exhaust pipe.

For this reason, the exhaust pulsation of the internal combustion engine is directly transmitted to the exhaust pipe, and this exhaust pulsation is transmitted as vibration to the vehicle body side of the automobile. There is an inconvenience that it deteriorates and is disadvantageous in practical use.

Further, even if a mass damper is provided in the exhaust pipe to remove the resonance frequency of the exhaust pipe from the normal rotation speed range, the vibration is not reliably reduced in the entire rotation speed range of the vehicle, that is, the resonance frequency of the exhaust pipe is reduced. There is an inconvenience that vibration is not reduced in the matching rotational speed region.

[Object of the Invention] Therefore, in order to eliminate the above-mentioned inconvenience, an object of the present invention is to provide an exhaust manifold connected to the exhaust system side of an internal combustion engine, and construct an exhaust pipe at the downstream end of the exhaust manifold. An exhaust pipe is connected and provided, a flexible tube is provided in the middle of the first exhaust pipe, and a catalytic converter for purifying exhaust gas is connected and provided at a downstream end portion of the first exhaust pipe, and the exhaust pipe is configured in the catalytic converter. The upstream end of the second exhaust pipe is connected to the second exhaust pipe, and a vibration isolation support member for attaching the second exhaust pipe to the vehicle body is provided, and vibration from the second exhaust pipe is provided near the vibration isolation support member of the second exhaust pipe. By providing a dynamic damper for avoiding the resonance frequency so as to cancel the vibration and arranging the anti-vibration support member closer to the catalytic converter than the dynamic damper, the vibration from the second exhaust pipe to the dynamic damper is generated. It avoids the resonance frequency when it is transmitted,
The purpose of the present invention is to realize a dynamic damper mounting structure for an automobile exhaust system capable of canceling vibrations from the exhaust pipe and reducing vibrations transmitted to the vehicle body.

[Means for Solving the Problems] In order to achieve this object, the present invention has an exhaust manifold connected to the exhaust system side of an internal combustion engine, and an exhaust pipe is formed at the downstream end of the exhaust manifold. A first exhaust pipe is connected and provided, a flexible tube is provided in the middle of the first exhaust pipe, and a catalytic converter for purifying exhaust gas is connected and provided at the downstream end of the first exhaust pipe. An upstream end of a second exhaust pipe that constitutes the exhaust pipe is connected to the second exhaust pipe, and a vibration isolation support member for attaching the second exhaust pipe to the vehicle body is provided, and a second exhaust gas is provided near the vibration isolation support member of the second exhaust pipe. The present invention is characterized in that a dynamic damper for avoiding a resonance frequency is provided in order to cancel the vibration from the pipe, and the vibration isolating support member is located closer to the catalytic converter than the dynamic damper.

[Operation] With the configuration as described above, when vibration is transmitted from the second exhaust pipe on the exhaust system side of the internal combustion engine to the dynamic damper, the dynamic damper prevents the resonance frequency from becoming a resonance frequency, and the second exhaust The vibration from the pipe is canceled out, and the vibration transmitted to the car body is reduced.

Embodiment An embodiment of the present invention will be described below in detail with reference to the drawings.

1 to 5 show an embodiment of this invention. In FIG. 2, reference numeral 2 is an internal combustion engine mounted on an automobile (not shown).

An intake manifold (not shown) and an exhaust manifold 4 are attached to the internal combustion engine 2. The upstream side flange portion 6a of the exhaust pipe 6 is fixed to the downstream side flange portion 4b of the exhaust manifold 4.

The exhaust pipe 6 has a catalytic converter 8 for purifying exhaust gas in the middle thereof, a first exhaust pipe 6-1 is arranged on the upstream side of the catalytic converter 8, and a second exhaust pipe 6-1 is arranged on the downstream side. The exhaust pipe 6-2 is provided.

A flexible tube 10 is provided in the middle of the first exhaust pipe 6-1.

The second exhaust pipe 6-2 is fixed to the vehicle body side (not shown) via an exhaust pipe mount bracket 12 which is a vibration-proof support member.

A dynamic damper 14 for avoiding a resonance frequency is provided in the vicinity of the mount bracket 12, which is a vibration-proof support member for the second exhaust pipe 6-2, in order to cancel the vibration from the second exhaust pipe 6-2. Is located closer to the catalytic converter 8 than the dynamic damper 14.

That is, as is apparent from FIG. 2, when the mount bracket 12 and the dynamic damper 14 are arranged, the mount bracket 12 is arranged on the upstream side of the dynamic damper 14.
Is provided.

More specifically, the dynamic damper 14 comprises a substrate portion 16, a weight portion 18, a connecting member 20 and a rubber 22, as shown in FIG.

That is, the substrate portion 16 is formed of a steel plate (SPHC), and the weight portion 18 is also formed of the same material as the substrate portion 16 in the shape of a square pole.

Further, the connecting member 20 connects the upper surface of the substrate portion 16 and the lower surface of the weight portion 18 and is formed of nitrile rubber (NR) and steel material for rivets (SBR).

Then, the rubber 22 is coated around the side surface of the weight portion 18.

In addition, the board portion 16 has two mounting hole portions 24-1, 24-for mounting the dynamic damper 14 to the second exhaust pipe 6-2.
Two are provided.

When comparing the case where the dynamic damper 14 is used and the case where it is not used, as shown in FIG. 3, only 100 mm behind the mounting position of the center hanger 30 that connects the exhaust pipe 6 and the vehicle body (not shown). The dynamic damper 14 shall be attached to the moved position.

 Next, the operation will be described.

The dynamic damper 14 is fixed to the second exhaust pipe 6-2 in the vicinity of the mount bracket 12, that is, the dynamic damper 14 is attached at a position moved 100 mm rearward from the attachment position of the center hanger 30.

By the way, at the time of acceleration of an unillustrated vehicle, as shown in FIG. 4, the electric power (dB) with and without the dynamic damper 14 is substantially over the entire range of 3000 to 7500 RPM except a part of the rotation range. Can be reduced, and especially the electric power (dB) is significantly reduced in the entire region near 5000 RPM. It can be confirmed that the vibration of the second exhaust pipe 6-2 in the vicinity of the mount bracket 12 is reduced by the dynamic damper 14 due to the reduction in the amount of electricity (dB).

Further, when decelerating an unillustrated automobile, as shown in FIG. 5, the dynamic damper 14 is used in substantially the entire range of 3000 to 7500 RPM except for a part of the rotation range, as in the case of the acceleration described above.
Electricity (dB) with and without
It is possible to reduce the electric power (dB), especially in the whole region around 5000 RPM.

As a result, the dynamic damper 14 can prevent the second exhaust pipe 6-2 near the mount bracket 12 from having a resonance frequency, and the vibration from the exhaust pipe 6 can be canceled out.
By being fixed to the second exhaust pipe 6-2 near 12, the vibration transmitted from the exhaust pipe 6 of the internal combustion engine 2 to the vehicle body (not shown) can be reduced, and the riding comfort of the vehicle can be improved.

Further, by positioning the mount bracket 12 closer to the catalytic converter 8 than the dynamic damper,
The dynamic damper 14 can be attached without changing the design of the second exhaust pipe 6-2, and it is possible to avoid making the manufacturing extremely difficult, which makes the manufacturing relatively easy and keeps the cost low. Therefore, it is economically advantageous.

Further, of the vibrations transmitted to the catalytic converter 8, the vibrations transmitted from the upstream side of the catalytic converter 8 are absorbed by the flexible tube 10 and are transmitted from the downstream side of the catalytic converter 8 via the mount bracket 12. The transmitted vibration is absorbed by the dynamic damper 14 located on the downstream side of the mount bracket 12, so that the vibration can be effectively absorbed and the upstream side and the downstream side of the catalytic converter 8 vulnerable to the vibration. It is possible to reliably reduce the vibration transmitted from the device and prolong the service life of the catalytic converter, which is economically advantageous.

[Effects of the Invention] As described in detail above, according to the present invention, an exhaust manifold is connected to the exhaust system side of an internal combustion engine, and a first exhaust pipe forming an exhaust pipe is provided at the downstream end of the exhaust manifold. A flexible tube is provided in the middle of the first exhaust pipe, and a catalytic converter for purifying exhaust gas is connected to the downstream end of the first exhaust pipe, and the exhaust pipe is formed in the catalytic converter. Provided by connecting the upstream end of the exhaust pipe,
An anti-vibration support member for attaching the second exhaust pipe to the vehicle body is provided, and a dynamic damper for avoiding a resonance frequency is provided near the anti-vibration support member of the second exhaust pipe to cancel the vibration from the second exhaust pipe to provide anti-vibration support Since the member is located closer to the catalytic converter than the dynamic damper, the dynamic damper can prevent the second exhaust pipe in the vicinity of the vibration-damping support member from having a resonance frequency and cancel the vibration from the second exhaust pipe. Thus, the vibration transmitted from the exhaust pipe of the internal combustion engine to the vehicle body can be reduced, and the riding comfort of the automobile can be improved. Further, by arranging the anti-vibration support member closer to the catalytic converter than the dynamic damper, the dynamic damper can be attached without changing the design of the second exhaust pipe, and the manufacturing can be relatively easy.
The cost can be kept low. Further, of the vibrations transmitted to the catalytic converter, the vibrations transmitted from the upstream side of the catalytic converter are absorbed by the flexible tube and transmitted from the downstream side of the catalytic converter via the vibration isolating support member. The vibration is absorbed by the dynamic damper located on the downstream side of the anti-vibration support member, so that the vibration can be effectively absorbed and transmitted from the upstream side and the downstream side to the catalytic converter which is weak against vibration. Vibration can be reliably reduced, and the service life of the catalytic converter can be extended, which is economically advantageous.

[Brief description of drawings]

1 to 5 show an embodiment of the present invention, FIG. 1 is an enlarged perspective view of a dynamic damper, FIG. 2 is a schematic explanatory view showing an internal combustion engine and an exhaust system of an automobile, and FIG. 3 is an exhaust of the automobile. FIG. 4 is a schematic explanatory view showing the system, FIG. 4 is an explanatory view showing a comparison with or without a dynamic damper at the time of acceleration of the automobile, and FIG. 5 is an explanatory view showing a comparison with or without a dynamic damper at the time of deceleration of the automobile. In the figure, 2 is an internal combustion engine, 4 is an exhaust manifold, 4b is a downstream flange portion, 6 is an exhaust pipe, 6a is an upstream flange portion, 6-1 is a first exhaust pipe, 6-2 is a second exhaust pipe, 8 is a catalytic converter, 10 is a flexible tube, 12 is a mounting bracket, 14 is a dynamic damper, 16 is a board part,
18 is a weight portion, 20 is a connecting member, 22 is rubber, 24 is a mounting hole portion,
30 is a center hanger.

Claims (1)

(57) [Scope of utility model registration request] 1. An exhaust manifold is connected to an exhaust system side of an internal combustion engine, and a first exhaust pipe constituting an exhaust pipe is connected to an end portion of a downstream side of the exhaust manifold. Is provided with a flexible tube, and a catalytic converter for purifying exhaust gas is connected to a downstream end of the first exhaust pipe, and an upstream end of a second exhaust pipe constituting the exhaust pipe is connected to the catalytic converter. And a vibration damper supporting member for mounting the second exhaust pipe to the vehicle body, and a dynamic damper for avoiding a resonance frequency in the vicinity of the vibration damper supporting member of the second exhaust pipe to cancel the vibration from the second exhaust pipe. Provided,
A dynamic damper mounting structure for an automobile exhaust system, wherein the vibration isolating support member is located closer to the catalytic converter than the dynamic damper.